Sludge pumping apparatus



Dec. 30, 1947.

G. R. TOLLEFSEN SLJUDGE PUMPING APPARATUS Filed Aug. 30, 1946 INVENTOR.

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Patented Dec 30, 1947 UNITED STATES PATENT QTFFEICE SLUDGE PUMPING APPARATUS George R. Tollefsen, Brooklyn, N Y. Application August 30, 1946, .Serial No. 694,053

3 Claims.

My invention relates to the art of transportation of heavy and viscous oils and oily sludges over great elevations and pumping them for considerable distances without interruption in the transmission operation. My invention is therefore especially adaptable for shipyard service as it can be used in the removal of heavy bunker oils and the oily viscous and watery sludge emulsions that collect at the "bottom of oil-burning vessels for their direct and uninterrupted discharge into the settling tanks of the shipyard power plant, where the emulsions are substantially broken down, the water drained off and the oily substances thereof reclaimed as fuel and burnt under the boilers in a conventional manner. I therefore describe my invention as it is applied to the cleaning of the fuel tanks of an oilburning maritime vessel, when it is tied up at a shipyard for bottom repairs.

It is a well known fact that in the length of time where heavy fuel oils are stored, an extremely viscous asphalt residue or sludge will settle on the bottom of the storage tanks, and as the sludge accumulation proceeds, the sludge accumulation becomes so substantial that it will seriously interfere with the pumping of the fuel oil, besides encroaching on the storage space for the pumpable fuel oil. The viscous nature of such sludges, especially when chilled through the waterswept ship bottom and mixed with leakage water, preclude their handling by ordinary pumping means and special methods and means have therefore been devised for the handling of such material.

:One of the important features of my invention is to expedite the sludge handling by providing a relatively small high vacuum receptacle, from which a high vacuum rotary pump continuously withdraws the material as it enters the tank. I am aware that many sludge pumping devices employ continuous conventional pumping from small vacuum receptacles, but all such attempts have been unsuccessful where vacuums of more than 15 inches, as indicated on the vacuum gauge are used. As the pumping of oily sludges over a ship side usually requires a vacuum of some 22 inches of mercury, such devices cannot be used for the shipyard service described.

I employ a high vacuum to raise the material over the ship side and suck it into an overside receptacle, while admitting air at the intake end of the transmission line. I employ a small vacuum receptacle from which a rotary pump continuously withdraws the aerated material as well as a substantial amount of air, which is 2 forced through a transmission line preferably into the settling tank of the yard power plant. Successful pumping of such aerated material has been done for a. distance of some 1,000 feet which should be sufficient for most any shipyard I service.

Now, therefore, I have discovered, and therein rests my claim to invention, that it is possible to use a small high vacuum receptacle together with a rotary pump that sucks aerated viscous material and air from .the receptacle before the air in the material has separated out therefrom, and which air afterwards in the long distance pumping substantially acts as a lubricant. Also by employing a float operated vacuum relief valve, I am able to prevent accidental carrying over of material into the high vacuum pump that I use to create the high vacuum required for the pumping. When the liquid level rises beyond a certain level, the float will open the vacuum relief and the high vacuum is instantaneously de-.

stroyed in the small receptacle; and the rotary pump, now assisted by atmospheric air and having a full pump suction, will rapidly lower the liquid level in the small receptacle and the air relief is shut off in such a short time that the viscous material inside the transmission hose has had no oportunity to lose momentum and aggregate or consolidate itself and float together and clog the hose. By this arrangement, I safeguard the high vacuum pump from accidental carrying over, and I also relieve occasional clogging so quickly that no steam blowing out of the transmissionflines is generally required,

In the drawing,

Figure 1 is a diagrammatic cross-sectional view through an oil burning vessel and my attendant sludge handling device is shown installed on a motor truck.

Figure 2 is a fractional cross-section of my preferred vacuum tank showing an enlarged detail of thefloat operated valve gear.

Figure 3 is a plan View showing the preferred arrangement of my device when installed on a motor truck.

Referring to the drawing in which like reference characters designate corresponding parts, l denotes an oil burning vessel and 2 is the small vacuum receptacle into which the sludge 3 that reposes in the ship bottom is to be pumped by my apparatus. My apparatus is composed of two distinct transmission lines, the vacuum trans mission line 4 that is adapted to be slung over the ship side and reach down to the bottom of the ship, and the pump transmission 5, through which the material is pumped to a convenient settling tank on shore by the rotary discharge pump 6. Mounted on the truck I is also a high vacuum pump 8, which connects to the receptacle by means of pipe 9. The pump suction I is shown connected to the lower portion of the tank. I prefer to install an open baflie plate ll, open at top and bottom and I prefer to provide a strainer l2 with relatively large openings between the bottom ofthe ballie plate and the tank side where the pump discharge is located. The tank top is also provided with a connection l3 to which the transmission hose 4 is attached. The float I4 is installed above the pump suction and is provided with the stem l5 which is free to move up and down in the fairleads l6 and H. The stem. is also provided with a cross-bar 18 that fits in a slot on the forked end of the lever IS. The lever I9 is hinged to the support 20 and is pivotally attached near its end to seat 2], which closes the air intake 22 when the lever is accentuated by the weight of the float I 4. A cleanout valve 23 is provided at the tank bottom.

At the end of the transmission hose 4, I prefer to provide an inlet nozzle 24 in the form of a pipe reducer provided with an inlet 25.

It is to be noted that in my device all transmission lines are preferably 4 inches in diameter, the tank 30 inches and the high vacuum pump has a volumetric displacement of some 700 cubic feet per minute and the displacement of the ro tary pump is 300 gallons per minute. The vacuum pump is shown driven by the motor 26 and the V-belt drive 21, and the motor 28 drives the rotary pump 6 by belt drive 30. The switchboard 3! is shown mounted on the'chassis of the truck and is connected to the electric plug-in 32.

The action of the sludge pumping apparatus is as follows:

The electric power is plugged in and the motors started and the end of the intake nozzle is inserted in the material to be pumped, care being taken not to submerge the air inlet 25. The material is now sucked up in a more or less broken up mass, which rushes through the hose and is violently discharged into the vacuum tank.. The operation of the system where heavy sludges are encountered is distinctly intermittent, and fluctuations in the tank vacuum are observed. When a mass of material is sucked up into the hose, the hose becomes more and more sealed and the vacuum increases in the tank and the built up sludge column in the suction hose snaps off at the air inlet and moves as a unit through the suction hose and is discharged into the vacuum tank, When the sludge column discharges into the tank and the air seal in the hose is broken, an instantaneous vacuum drop occurs in the tank. The atmospheric air that has entered through the inlet 25 is intimately mixed into the sludge column, which contains m nute air bubbles throughout its bulk. When the sludge mass is discharged into the tank, it is therefore thoroughly aerated, and it will take some time for the air bubbles to free themselves from the viscous material into which they are imprisoned. In my device, however, the air bubbles are not allowed to separate out as the pumped sludge is continuously being withdrawn by the rotary pump as fast as it enters the tank. Therefore, a thoroughly aerated mass is pumped into the transmission line 5. The rotary pump is selected so as to handle about four times the amount of sludge that the vacuum pump can suck into the tank and therefore the pump suction from this tank is always only partly submerged, and a substantial amount of air is also taken out from the tank and pressed into the discharge line 5 of the system. It is a wellknown fact that air admitted to a transmission line for viscous oils will substantially relieve the clinging tendency of the material to the pipe side and enable the operator to pump through much longer distances than if the line was completely filled by viscous material.

The action of the float operated vacuum relief is self-explanatory. Figure 1 shows the weight of the float pressing the seat on the atmospheric relief opening, and Figure 2 shows the seat lifted from the passage by the float. In the small vacuum receptacle, a single sludge discharge of viscous material will sufiice to lift the valve seat, and therefore the vacuum relief will always occur at the moment a mass discharge has taken place and a relatively low vacuum exists in the receptacle as atmospheric air enters the receptacle through a substantially empty hose line. The vacuum relief is therefore instantaneously cffected and as the discharge pump is of ample capacity to momentarily drain out the surplus material from thesmall vacuum receptacle, the

high vacuum is directly reestablished, and the whole vacuum relief operation takes place in the matter of seconds instead of minutes, that lapse before the required high pumping vacuum is reestablished in the large vacuum tanks that are characteristic of the Wheeler pumping rigs,

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. Apparatus for evacuating viscous material comprising a relatively small receptacle, a conduit connected at one end to deliver into said receptacle, the other end of the conduit being adapted to be immersed in said material, the conduit having means to admit air into it adjacent said other end to aerate the material passing through said conduit to said receptacle, means for creating a high vacuum in the receptacle, an evacuating pump connected to the receptacle, an outward opening valve in the receptacle and a float in the receptacle connected to the valve to operate said valve and control the vacuum.

2. Apparatus for evacuating viscous material, comprising a relatively small tank containing a vertical baffle member spaced from the top and bottom thereof, a conduit connected to deliver said material to the tank on one side of the baffle member, an evacuating pump connected to communicate with the tank at the opposite side of said baffle member, a strainer adjacent the lower part of the bailie member between the interior surface of the tank and said opposite side, means for creating a vacuum in said tank and means controlled by the level of the contents of the tank between the wall thereof and the bailie member and above said strainer to regulate the vacuum in the tank.

3. Apparatus for evacuating viscous material comprising a, relatively small receptacle, a conduit connected at one end to deliver into said receptacle, the other end of the conduit being adapted to be immersed insaid material, the conduit havin means to admit air therein adjacent said other end to aerate the material passing through said conduit to said receptacle, means for creating a high vacuum in the recep tacle and means fordischarging said material therefrom, and a member in'said receptacle controlled by the level of the liquid therein, said receptacle having an atmospheric opening, an outwardly opening valve element for quickly opening and closing said opening and connected to said member to be operated thereby to lower and restore the vacuum in said receptacle before the material in the conduit can clog same.

GEORGE R. TOLLE'FSEN.

REFERENCES orrEn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name I Date 566,625 Savorgnan Aug. 25, 1896 1,698,127 Engstrand Jan. 8, 1929 1,883,594 Cross Oct. 18, 1932 

